When, where to use SMV signs

So you think you know all there is to know about using slow moving vehicle signs? Unless you read Indiana legal code at bedtime every night, you might be surprised.

Fred Whitford, head of Purdue University Pesticide Programs, and Mike Templeton, a transportation consultant, Clayton, emphasize the need to use SMVs correctly when they address farmers at programs around the state.

Key Points

• Law requires slow moving vehicle signs for speeds slower than 25 miles per hour.

• Cover the SMV on a tractor or implement hauled on a trailer above 25 mph.

• SMVs can mark driveways as long as the sign is on private property.

Here are key questions and answers about SMVs, lifted from “Transporting Farm Equipment — What Growers Need to Know,” Purdue Extension Bulletin PPP-83.

Question: What vehicles require SMVs?

Answer: They’re required by law when a slow moving vehicle is pulled, towed, self-propelled or drawn by an animal and isn’t ordinarily moved or operated at speeds greater than 25 miles per hour.

Question: Where must the sign be mounted?

Answer: It must be mounted 3 to 5 feet from the pavement and as near the center as possible.

Question: Are there situations where you could use red flags?

Answer: Tractors and towed equipment are exempt from legal dimensions. It’s recommended, but not required, that vehicles with flashers go in front of and behind a tractor pulling a disk extending into the left lane, for example. Red flags to mark the end of the implement extending into the left lane are allowed and are considered a good safety option.

Question: Do I have to have an SMV on the implement towed?

Answer: A single SMV on the tractor meets the requirement, as long as the equipment in tow doesn’t obscure it. However, it’s a good idea to have one on the tractor and on each piece of equipment towed.

Question: What if I’m towing an implement or moving it on a trailer behind a truck — do I need to cover the SMV?

Answer: It’s probably best to remove it, cover it or load the equipment so the SMV isn’t visible. That lessens chances for varied interpretations by law enforcement officers.

Question: Where would I mount an SMV on a manure spreader where it’s not practical to put it in the center?

Answer: If it’s impractical to mount it anywhere else, mount it on the side at the rear of the implement.

Question: Would I really need an SMV on the back of a low-profile manure spreader?

Answer: You wouldn’t need it as long as the SMV on the back of the tractor is not obstructed by the spreader.

Question: Are slow moving vehicle signs required for trailers or semi-trailers?

Answer: No. Their normal speed exceeds 25 miles per hour.

Question: Is the use of a SMV to mark a driveway illegal?

Answer: This is not an illegal use as long as the sign is on private property.

Editor’s note: This is not intended as legal advice. For specific questions, visit www.btny.purdue.edu/ppp or e-mail fwhitford@purdue.edu.


Play it safe: SMVs protect you both physically and legally.

This article published in the July, 2010 edition of INDIANA PRAIRIE FARMER.

All rights reserved. Copyright Farm Progress Cos. 2010.